Ironman Run Training: 10 Key Workouts

SUMMARY:
This post presents 10 key Ironman run workouts designed to improve endurance, pacing control and resilience across the marathon distance. From long aerobic runs to strategic race simulations, each session targets a critical element of race-day success. These workouts help you build fatigue resistance, refine fuelling strategies and strengthen your mindset, so you can run strong after 180K on the bike and cross the finish line with confidence.

Built to Go the Distance

The Ironman 70.3 run isn’t just about grit, it’s about strategy. By the time you hit the pavement, your legs are already toasted from the swim and bike. That’s why your run training needs more than mileage. To run strong off the bike, you need sessions that build fatigue resistance, sharpen pacing and harden your mental game. It’s not just about speed, it’s about durability, pacing and strategic endurance. These 10 key Ironman run sessions will help you build the strength, resilience, and confidence needed to power through 42.2 km on race day!

Ironman Run Training Zones: HR, RPE and Effort Guide

Understanding your run training zones is the key to structuring smarter sessions and building endurance without burnout. Use this guide to align your heart rate, RPE and pacing effort across all five zones.

• Zone 1 (Recovery): 68–73% max HR / RPE 1–2 - very easy jog for circulation and recovery

• Zone 2 (Endurance): 73–80% max HR / RPE 3–4 - easy aerobic effort, conversational pace

• Zone 3 (Tempo): 80–87% max HR / RPE 5–6 - comfortably hard, sustainable over time

• Zone 4 (Threshold): 87–93% max HR / RPE 7–8 - hard, just below redline

• Zone 5 (VO2 Max): 93–100% max HR / RPE 9–10 - short, intense efforts

Use FLJUGA’s free Heart Rate Zone Calculator to dial in your Ironman training zones with precision.

10 Essential Ironman Run Sessions!

1. Long Endurance Run

Purpose: Build aerobic capacity and fuel efficiency

Warm-Up: 12 min jog
Main Set: 90–120 min @ Zone 2
Cool-Down: 10 min jog

2. Broken Tempo Blocks

Purpose: Develop aerobic strength through structured Zone 3 reps

Warm-Up: 12 min jog
Main Set: 4 x 10 min @ Zone 3 (3 min jog between)
Cool-Down: 10 min jog

3. Progressive Run Build

Purpose: Gradually increase intensity to threshold finish

Warm-Up: 12 min jog
Main Set: 15 min @ Zone 2 + 15 min @ Zone 3 + 10 min @ Zone 4
Cool-Down: 10 min jog

4. Long Tempo Finish

Purpose: Train strength to hold pace under late fatigue

Warm-Up: 10 min jog
Main Set: 60 min @ Zone 2 + 20 min @ Zone 3
Cool-Down: 10 min jog

5. Double Threshold Set

Purpose: Raise aerobic ceiling with high-quality Zone 4 work

Warm-Up: 12 min jog + strides
Main Set: 2 x 15 min @ Zone 4 (5 min jog between)
Cool-Down: 10 min jog

6. Alternating Pace Run

Purpose: Prepare for effort shifts during race pacing

Warm-Up: 12 min jog
Main Set: 4 x (5 min @ Zone 2 + 10 min @ Zone 3)
Cool-Down: 10 min jog

7. Intervals off Fatigue

Purpose: Build pacing control and mental focus after sustained aerobic load

Warm-Up: 12 min jog
Main Set: 40 min @ Zone 2 + 4 x 5 min @ Zone 3 (2 min jog between reps)
Cool-Down: 10 min jog

8. Threshold + Tempo Combo

Purpose: Train strong pacing control at multiple intensities

Warm-Up: 12 min jog
Main Set: 10 min @ Zone 4 + 20 min @ Zone 3 + 10 min @ Zone 4
Cool-Down: 10 min jog

9. Mid-Long Tempo Continuous

Purpose: Sustain Ironman pace under focused aerobic load

Warm-Up: 12 min jog
Main Set: 60 min @ Zone 3
Cool-Down: 10 min jog

10. Race Simulation Run

Purpose: Simulate Ironman effort across multiple zones

Warm-Up: 10 min jog
Main Set: 30 min @ Zone 2 + 20 min @ Zone 3 + 10 min @ Zone 4
Cool-Down: 10 min jog

Bonus Tip: Focus on Consistency and Pacing

High-intensity intervals have a place, but the true secret to Ironman run success is consistent, smart training, not smashing every workout. Train your body to move efficiently under fatigue and prioritise proper nutrition and hydration every step of the way.

Common Mistakes with Ironman Run Training

Even experienced athletes can slip into bad habits during long-course run prep. Avoid these common errors to stay consistent and strong.

• Running Too Hard on Easy Days
  Pushing the pace too often in Zone 1 and Zone 2 runs limits aerobic gains and increases injury risk.

• Neglecting Nutrition Practice
  Failing to test race-day fueling strategies during long runs can lead to GI issues or energy crashes when it counts.

• Skipping Brick Runs
  The ability to run well off the bike is earned. Skipping bricks leaves you underprepared for race-day fatigue.

• Ignoring Recovery Weeks
  Without proper recovery, your performance stagnates. Build in rest to allow adaptations to take hold.

Stay patient, stay consistent and remember that smart training always beats reckless effort.

FAQs: Ironman training

How many runs per week for Ironman training?

Most athletes run 3–4 times per week, balancing long runs, tempo work and recovery.

Should I do speed work for Ironman?

Some speed work is beneficial, but most training should stay aerobic and focused on sustainable paces.

How do you pace the Ironman marathon?

Start conservatively, run by heart rate or perceived effort early and aim for even or negative splits. Many athletes run the first half easier than the second.

FURTHER READING: BUILD BRICK STRENGTH

• Ironman Training: What Is Zone 2 / Endurance?

• Ironman Training: What Is Zone 3 / Tempo?

• Ironman Training: What Is Zone 4 / Threshold?

• Ironman Training: What Is Zone 5 / VO2 Max?

• Ironman Bike Training: 10 Essential Workouts

• Ironman Swim Training: 10 Essential Sessions

• Ironman Training: Recovery Week

• Ironman: Beginner’s Guide

Final Thoughts

The Ironman marathon is as much about mental strength and pacing discipline as it is about physical endurance. You’re not just running 42.2 km, you’re running it after hours of swimming and cycling. That demands strategic, specific preparation. These 10 sessions give your training the structure it needs to prepare your body and mind for the final leg. Whether it’s a long Zone 2 aerobic run, a brick session to simulate fatigue or a race-paced progression effort, each workout contributes to your ability to stay in control when it matters most.

Train smart, fuel well and respect the long game. The more you simulate race-day stress in training, the more ready you’ll be to meet it with confidence. Strong Ironman marathons aren’t accidental. They’re built, one purposeful session at a time.

Which key run session will you add to your training first to build the strength and stamina you need for Ironman success?

Always consult with a medical professional or certified coach before beginning any new training program. The information provided is for educational purposes only and is not a substitute for personalized advice.